Johnny280

Two days of wrenching later, the Z now has a full Zstory exhaust plus Header (a little bit tricky with the orginal heatshield) and the vacuum lines were rerouted. The Vacuum advance is now at the right nipple as is the carbon canister signal line. They both seem to work fine - vacuum advance is advancing and signal line is signaling. As expected the servo diaphragm and control valve are really doing nothing in this setup and could be completely removed. After setting the timing to 10 BDC (timing was pretty off) and checking if the mechanical advance and vacuum advance are fine i readjusted the carbs using a colortune and a syncrometer. I had to lean it out half a turn to get it out of the yellow into a rich blue (the 'raise the piston by 2mm' and 'get the highest idle' methods never worked for me so i tried that colortune) - i guess this is normal after timing and new headers? It runs great now, the throttle is very responsive and apart from the fact that it is still super loud and a little 'drowny' at 60-65mph, which i wanted to fix with changing the old manifold and 'mystery' middle secition to Zstory complete (Muffler was already the 'classic' version). Anyway the sound is really impressive and maybe i am just getting old and the noise level is normal : / @Geoff and Mark about this idle waver: It is still there and i really listened to it more closely and i was wrong with the 3-5 seconds frequency it is more like 1-2 seconds. And i had the feeling that it even persists during steady cruise. Like the car wants to accelerate a tiny amount and then drops back but ever so slightly. I will try to have a look at the pistons if they are moving. Maybe this could also be a tiny vacuum leak, because i experienced the same issue much more pronounced after i destroyed the first vacuum advance hose on the hot exhaust ?. It felt the same but tenfold in magnitude.

Thanks for the Info I will reroute both carbon canister and vacuum advance to that ported vacuum source. Regarding dyslexia I blame Television and maybe my foreign origin : / Will keep your advice in mind about the AC when it is running again.

Thanks for answer. I checked behind the front carb dome and there is a capped of nipple. I will connect the vacuum line to that source, cap of the one on the balance tube (or run a vacuum line to the carbon canister from here) and set the ignition timing. And for FCID=>FICD I will try better next time ? But will the engine run fine without raising the rpm if the AC is running?

Hi, right now i am in the process of fixing all small issues with my Fairlady. Since you guys already helped me I want to try my luck a second time. I had a look at the vacuum lines and to me they seem to be set up in a weird way. The car is a '78 280Z with a 280ZX engine (L28E F54 block with P79 head) converted to Ztherapy SU carbs and original AC. The engine runs fine apart from a slight fluctuation in idle speed (every 3-5 second it goes up from 800rpm to maybe 840rpm and then back down again). I checked all the FSMs to use the correct terms in my drawing and I added three pictures of the current situation. Especially the wrong plumming of the servo diaphragm and control valve +the missing connection to the carbon canisters vacuum signal line seems odd to me. If i understand the original piping correctly then I would expect that the servo diaphragm is doing nothing in this setup (have to check if it moves during let go of the throttle) and that the carbon canister is only doing its job in 'idle mode' due to the bypass mentioned in the haynes manual (because the valve for the purge line is never opened by the vacuum signal line). Another point is the missing of the EFI specific FCID. The AC is not working at the moment so i don't know if the car runs fine without raising the idle rpm. I wonder if it would make sense to pipe the FCID magnet valve to the control valve to use it as a 'carb FCID'? My overall question to the experts is 'Do i need to be concered about this vacuum setup (do i need the servo diaphragm/carbon canister to do their work) or is this maybe a clever solution?' Thanks in advance for your time and help. Picture 1: Picture 2. Picture 3.

Hi, finally found the time to check both problems. For the Shift Knob it was really the inlet buzzing (without knob/ with knob without inlet everything is fine). So I will try to glue it back in place with some better glue. The drum brake noise came from a bent edge on the backplate (thx for the hint zed head). Wheelbearing play was minimal. After pulling the drum it was pretty obvious which part was rubbing (ground some nice groove into half of the cooling fins). Thank you all for your help.

Ok, thanks for all replies i will check for any play/ anything suspicious and try it without the shift knob.

I guess you will like this one. Btw those are two German Fairladys including old german style plates and euro spec airdam. Oh and she likes horses too:

Hi, i have some (hopefully) easy to fix problems with my 1978 280Z. The car has a pre '81 5 speed in it with a R200 diff. The first problem is a buzzing/mild grinding noise coming from the gearshifter especially in 5th gear, which gets louder the fast you drive. I checked different forums for this problem and the suggested solution was always checking the bushings and plastic cap on the stick. I did that, they are Nissan OEM parts in pristine condition ( is suspect a previous owner swapped them). I am pretty much clueless right now if this is just normal or a serious problem with the gearbox. The noise dissapears if you hold the stick tight in the right position. My second problem is a noise coming from the left rear drum brake during right hand cornering. It makes a 'grind grind grind grind grind' noise (faster with higher speeds). Not particular loud or alarming - it is more on the embarassing side. What do you think could be the reason for this? - worn springs/brake pads - uneven drum - broken wheel bearing - loose backing plate - Anything else? Thanks in Advance for your help. Best Regards Johnny